However, you probably aren’t familiar with how they ended up with their current monikers.

Mila Kunis -- Milena Markovna Kunis

At the age of seven, Milena Markovna Kunis and her family moved from Ukraine to Los Angeles, Calif.

Mila's mother, Elvira, and father, Mark, soon enrolled her in acting classes and allowed Mila to shorten her name when she started booking her first roles on 'Days of our Lives,' '7th Heaven,' and playing a young Angelina Jolie in 'Gia.'

Joaquin Phoenix -- Joaquin Rafael Bottom/Leaf Phoenix

Joaquin Rafael Bottom is the third of five children, all with equally interesting names, including River (1970 -- 1993), Rain (1973), Liberty (1976), Summer, and a half-sister Jodean.
After Joaquin's parents, John Lee and Arlyn Bottom, married in 1969, the couple joined the religious cult the Children of God and traveled around South America. But they soon became disenchanted with the cult and moved back to the U.S. in 1978, where they changed their last name to 'Phoenix' to symbolise 'new beginning.'

Around this same time, a young Joaquin began calling himself 'Leaf,' desiring to have a similar nature-related name like his siblings. In a past Jay Leno interview, Joaquin said he had originally called himself 'Antleaf' as a child.

Leaf would become the name he would use as a child actor until, at age 15, he changed it back to Joaquin.

Reese Witherspoon -- Laura Jeanne

Katy Perry -- Kathryn (Katy) Hudson

Before she was a chart-topping singer, Perry was producing Christian music under her birth name, Kathryn Hudson. She released gospel record 'Katy Hudson' under the former label Red Hill Records before adopting her mother's maiden name to avoid confusion with actress Kate Hudson.

Christopher Walken -- Ronald Walken

The change in name came about after singer Monique Van Vooren, whom Walken worked for at the time, renamed him Christopher for no real apparent reason. The name stuck, though his friends still call him Ronnie.

Natalie Portman -- Natalie Herschlag

After being born in Jerusalem, Israel, in 1981 to an Israeli gynecologist father named Avner Hershlag and American mother named Shelley Stevens (her mother's family changed their last name from 'Edelstein' to 'Stevens' when arriving in the U.S. from Russia and Austria), Portman now holds dual American and Israeli citizenship.

Lorde -- Ella Marija Lani Yelich-O'Connor

'I thought 'Lord' was super rad, but really masculine -- ever since I was a little kid, I have been really into royals and aristocracy,' Lorde told Interview magazine. 'So to make Lord more feminine, I just put an 'e' on the end! Some people think it's religious, but it's not.'

Louis C.K. -- Louis Szekely

Whoopi Goldberg -- Caryn Elaine Johnson

The actress and 'The View' correspondent didn't become Whoopi Goldberg until, while working in a theatre in San Diego, friends noticed she had a bit of a flatulence problem and began calling her Whoopi after a whoopee cushion.

'If you get a little gassy, you've got to let it go,' Whoopi has said. 'So people used to say to me, 'You're like a whoopee cushion.' And that's where the name came from.'

It was Whoopi's mother who felt her daughter should take a Jewish-sounding last name to advance her Hollywood career. And thus Whoopi Goldberg was born.

Drake -- Aubrey Drake Graham

When he played wheelchair-bound Jimmy Brooks on the Canadian TV show 'Degrassi,' the actor went by the name Aubrey Graham. But when the Toronto native switched his career focus to rapping in 2009 after signing a recording contract with Lil Wayne's Young Money Entertainment, he started using one name only: Drake.

Miley Cyrus -- Destiny Hope Cyrus

Over the years, the nickname became shortened to Miley. Cyrus legally changed her name in 2008.

Julianne Moore -- Julie Smith

The Oscar-nominated actress told The New York Times in 2001 she decided to take up acting after a suggestion by her drama teacher. Moore didn't want to change her name, but said it was too popular to stand out.

Instead, she adopted a name that honored both her parents.

''There was already a Julie Smith, a Julie Anne Smith, there was everything,'' Moore told the NYT. ''My father's middle name is Moore; my mother's name is Anne. So I just slammed the Anne onto the Julie. That way, I could use both of their names and not hurt anyone's feelings. But it's horrible to change your name. I'd been Julie Smith my whole life, and I didn't want to change it.''

Jamie Foxx -- Eric Marlon Bishop

Nicki Minaj -- Onika Tanya Maraj

The rapper doesn't even like her stage name. According to an interview with The Guardian, Minaj grew up with nicknames Nicki and Cooky. Nicki Minaj was the name given to her during one of her earliest production deals.

'Somebody changed my name,' Minaj said. 'One of the first production deals I signed, the guy wanted my name to be Minaj and I fought him tooth and nail. But he convinced me. I've always hated it.'

Ludacris -- Christopher Brian Bridges

'The nickname is something I made up,' said Ludacris. 'Part of me is calm, cool, and collective, while the other side is just beyond crazy.'

Before becoming a rapper, Ludacris was known as 'Chris Luva Luva' on Atlanta's Hot 97.

Meg Ryan -- Margaret Mary Emily Anne Hyra

Born in Fairfield, Conn., to Roman Catholic parents named Susan Jordan and Harry Hyra, Margaret Mary Emily Anne Hyra changed her name to Meg Ryan after she dropped out of NYU one semester early to pursue her budding acting career.

Oprah Winfrey -- Orpah Winfrey

'My Aunt Ida had chosen the name, but nobody really knew how to spell it, so it went down as 'Orpah' on my birth certificate, but people didn't know how to pronounce it, so they put the 'P' before the 'R' in every place else other than the birth certificate. On the birth certificate it is Orpah, but then it got translated to Oprah, so here we are.'

According to a 2003 'Inside the Actors Studio' interview, Martin Sheen revealed he took his name from CBS casting director Robert Dale Martin, who gave him his big break, and a Catholic televangelist, Fulton J. Sheen, whom he thought was a great actor. Unlike his son Charlie, Martin never legally changed his name.

Emilio Estevez (right), of course, kept his name.

Dakota Fanning -- Hannah Dakota Fanning

The youngest nominee ever for a Screen Actors Guild Award, Hannah Dakota Fanning goes by her middle name professionally instead of her legal first name.

Fanning, whose mother Heather Arrington played professional tennis (her father, Dakota's grandfather, was NFL player Rick Arrington) and father, Steven Fanning, a former minor league baseball player, is of Irish and German ancestry.

Michael Caine -- Maurice Joseph Micklewhite

In 2009, Caine explained re-naming himself after Humphrey Bogart's character in 'The Caine Mutiny' to New York Magazine.

'Bogart was my hero, and even though he came from a sort of snobby, aristocratic family -- he was a distant relation of Princess Diana -- when I was a kid I thought he was a tough guy,' said Caine. 'Any person with my working-class background would be a villain or a comic cipher, usually badly played, and with a rotten accent. There weren't a lot of guys in England for me to look up to.'

Tina Fey -- Elizabeth Stamatina Fey

That's right. Fey shares the name of her '30 Rock' Liz Lemon character. Her stage name is just a shortened version of her middle name.

Bono -- Paul David Hewson

The U2 frontman and humanitarian we all know as Bono wasn't actually born with just one name. Before he became world famous, the Irish musician was known by the name Paul David Hewson. But his wife still reminds Bono of his roots, going by the name Ali Hewson.

The name Bono was originally a nickname, short for 'Bono Vox' meaning 'good voice' in Latin, said to be given by his friend Gavin Friday.

Lady Gaga -- Stefani Joanne Angelina Germanotta

Twenty-six-year-old Stefani Joanne Angelina Germanotta was born and raised in New York City.

Chevy Chase -- Cornelius Crane Chase

Cornelius Crane Chase was named after his mother's adoptive father, Cornelius Vanderbilt Crane, heir to the successful New York company, Crane Plumbing.

The nickname Chevy was given by his grandmother, from the medieval English 'The Ballad of Chevy Chase.' As a descendant of the Scottish Clan Douglas, she felt the name 'Chevy' seemed fitting.

Portia de Rossi -- Amanda Lee Rogers

The 'Arrested Development' actress told advocate.com in 2005 she changed her name legally at the age of 15 to reinvent herself after coming out as gay.

The name Portia is from a Shakespearean character in 'The Merchant of Venice.' She chose an Italian last name:

'De Rossi because I was Australian and I thought that an exotic Italian name would somehow suit me more than Amanda Rogers. When you live in Australia, Europe is so far away and so fascinating, so stylish and cultured and sophisticated.'

Spike Jonze -- Adam Spiegel

The director of critically acclaimed 'Her' got his pseudonym from co-workers of a Rockville BMX store because 'he'd come to work without showering, and his hair was usually sticking straight up,' according to New York Magazine.

Jodie Foster -- Alicia Christian Foster

Foster's estranged brother Buddy claims her name change to 'Jodie' came as the result of a nickname, the code, 'Jo D' for their mother's partner, Josephina Dominguez, in his book, 'Foster Child: A Biography of Jodie Foster.'

Bruno Mars -- Peter Gene Hernandez

Mars changed his Puerto Rican name 'to avoid being stereotyped' into performing solely Latin and Spanish music, according to GQ.